word-forming element meaning "together, with," sometimes merely intensive; it is the form of com- used in Latin before consonants except -b-, -p-, -l-, -m-, or -r-. In native English formations (such as costar), co- tends to be used where Latin would use con-.

c. 1300, formen, fourmen, "create, give life to, give shape or structure to; make, build, construct, devise," from Old French fourmer "formulate, express; draft, create, shape, mold" (12c.) and directly from Latin formare "to shape, fashion, build," also figurative, from forma "form, contour, figure, shape" (see form (n.)). From late 14c. as "go to make up, be a constituent part of;" intransitive sense "take form, come into form" is from 1722. Related: Formed; forming.

"one who conforms" in any way, 1630s, from conform + -ist. Compare conformism. Originally usually with reference to religion, "one who complies with the form of worship of the Church of England."

late 15c., "corresponding in form or character, resembling," 1510s; see conform + -able. Meaning "compliant, ready to follow directions" is from 1520s. Related: Conformably; conformability.

1890, "tendency or need to conform" to some group standard, from conform + -ism. In religion, from c. 1902. In geology from c. 1912. Modern, general sociological sense (social conformism) popularized from c. 1948.

also non-conforming, "failing or refusing to conform," 1640s, from non- + conforming (see conform). Originally in religion, "refusing to follow the forms and regulations of the Church of England;" see nonconformist.